Water-tube boiler.



No. 840,566. PATENTED JAN. 8, 1907.

- s. P. JETER.

WATER TUBE BOILER.

APPLICATION FILED 001. s. 1900.

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fl K Q BY fl I I ATTORNEYS 1w: NORRIS PETERS cm, WASHINGTON, a. c.

No. 840,566. PATENTED JAN. 8, 1907.

" s. P. JETER.

- WATER TUBE BOILER.

APPLICATION nun 00125. 1906.

2 SHEETS-SHEET 2.

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WITNESSES: 1 INVENTOR.

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ATTORNEYS fHE NORRIS PE1ERS co, WASHINGTON. o. c

UNITED STATES PATENT OFFICE.

WATER-TUBE BOILER.

Specification of Letters Patent.

Patented Jan. 8, 1907.

Application filed October 5, 1906- Serial No. 337,654.

To all whom it may concern:

Be it known that I, SHERWOOD F. J ETER, a citizen of the United States, and a resident of the city and county of New Haven,-State of Connecticut, have invented new and useful Improvements in Water-Tube Boilers, whereof the following, in connection with the drawings, is a specification.

My invention relates especially to watertube boilers composed entirely or in part of headers or drums connected together by nests of tubes extending from the heads of such drums or headers, the heads into Which the tubes are fastened being known as tubeplates. It has been the practice heretofore in boilers of this type for high ressures to make the tube-plates when not raced with internal stay-rods in form of a segment of a sphere, because a drum having heads of this form is theoretically best capable of resistin without distortion strains caused by interna pressure. I have found, however, that when the drums are connected together by tubes in the above-described manner the conditions to which the tube-plates are subjected under pressure are quite iiferent from those which would prevail if the drums were not so. connected. In actual practice I have found that the effect of internal pressure upon a water-tube boiler thus constructed is to bring the inner tubes in compression, which braces My invention consists of a construction of tube-plate strengthened at its periphery by forming deepcorrugations in the outer edge of the tube-plate, which extend inward between the outer series of tubes, whereby the .tendency of said tube-plate to-be deformed at and near its periphery is greatly reduced.

In the drawings, Figure 1 is a top plan view of a tube-plate constructed according to my invention. Fig. 2 is a cross-section on the line 1 1 in Fig. 1. Fig. 3 is a crosssection on the line 2 2 in Fig. 1. Fig. 4 is a unit/"socalled, showing a pair of drums connected by a nest of tubes, the drums being broken away to show the tube-plates in cross-section and said tube-plates being of the ordinary spherical form. But one transverse row of tubes in front of the section-line of the tube-plates is shown in this figure, the other tubes being omitted to avoid confusion. Fig. 5 is a similar unit, shown as provided with my improved tube-plates. Only the outer row of tubes on the side nearest the eye is shown in this figure, the other tubes being omitted to avoid confusion. The general arrangement of the Whole nest of tubes is indicated in Fig. 1.

In all figures similar letters of reference indicate like parts.

A is the tube-surfacethat is to say, the face of the tube-plate in which the tubes are inserted.

B B B are holes for the tubes.

D is the flange of the tube-plate.

O C C are depressions formed in the external periphery of the tube-plate, extending from the flange into the tube-surface and merging into the tube-surface between the outer series of tube-holes. The depressions C C C are formed in a die.

E E in Fig. 4 represent one transverse, row of tubes in front of the section-line of the tube-plate.

E E in, Fig. 5 represent the outer row of tubes on the side nearest the eye. The dotted lines E E represent the curvature which is developed in the outer tubes of this type of boilers when the same are subjected to internal pressures.

By subjecting a boiler unit of the type indicated in Fig. 4 to an internal pressure of five hundred pounds to the square inch each of the outer tubes was forced outward, as indicated in the dotted lines in Fig. 4, more than one-half an inch, measured midway of their length from their normal position, whereas the same test, applied to a similar unit provided with my improved tube plates, showed a displacement of less than half that amount, measured at the same place, indicating greatly-increased stability in the form of tube-plate at the lace where stability is most needed. The iscovery of the fact that the inner group of tubes in boiler units of this type is in compression also does away with the supposed necessity for making the tube-surface when not internally braced in the form of a segment of a series of tubes.

sphere. I prefer to make the tube-surface of my tube-plates flat, because a flat surface is much easierto drill or punch and because the connecting-tubes between the two heads may all be of the same len th.

I am aware that tube-plates for boilers of the described type have been made with a flat tube-surface, braced by internal stayrods, and my improvement is'also adapted to such braced tube-plates for the reason that the actual operation of such stay-rods is no r to stiffen the tube-plate at and near its periphery, but in some degree to transmit to some of the interior tubes the tension which would otherwise be transmitted wholly to the outer It is, however, impracticable to so distribute the stay-rods as to equaliz e strains over the whole tube-surface of the tube-plate, because the stay-rodswould then obstruct access to the tubes in cleaning or repairing the boiler, and the outer periphery of such tube-plates remains subject to distortion and in need of stiffening by my im proved construction.

I do not confine myself to tube-plates of circular form.

Having now described my invention, what I claim, and des re to secure by Letters Patent, is-

1. A tube-plate, comprising a tube-surface, and a flange, provided with a series of depressed ribs in the periphery of the tubeplate, extending from the flange to the tubesurface, and merging into the tube-surfaee,

substantially as and for the purposes set forth.

2, A tube-plate, comprising a tube-surface, a flange, and a rounded corner between said tube-surface and flange, provided with a series of depressed ribs formed in said rounded corner, the bottoms of said ribs extending diagonally from the periphery of the flange into the tube-surface, substantially as and for the purposes set forth.

3. A water-tube boiler, comprising a pair of headers connected by a nest of tubes, the opposing tube-plates of said headers construeted witha series of depressed ribs formed in their respective peripheries, and extending from the flanges of said tube-plates diagonally to the tube-surface between the outer series of tubes, substantially as and for the purposes set forth.

4. In a water-tube boiler, the combination with the tubes; of a tube-plate co1nprising a tube-surface having a series of holes for the tubes, a flange substantially at right angles to the tube-surface, and a series of depressed ribs extending diagonally from the flange into the tubesurface between the outer series of tubes, substantially as described.

In witness whereof I have hereunto set my hand on the 3d day of October, 1906.

SHERWOOD F. JET'ER.

Witnesses:

JOHN K. BEACH, WALLACE S. Moms. 

